The exercise is basiacally asking for the perimeter of the garden. The perimeter of a rectangle is twice the sum of its dimensions, so we have

Answer: a. 10%
Step-by-step explanation:
Girls in the class = 40%
Girls play tennis = 25%
Percentage of class play tennis = 40%*25% = 0.4*0.25 = 0.1
Percentage of class play tennis = 10%
The nearest whole number would be 93 because you round up if the decimal place is greater than 5 and down if it's less.
You can pick a symbol, maybe m or z to be the symbol.